RF2516
Pin
11
Function
VREF P
Description
Interface Schematic
Bias voltage reference pin for bypassing. The bypass capacitor should be of
appropriate size to provide filtering of the reference crystal frequency and
be connected directly to this pin. Diodes shown in the interface schematic
provide 3kV electrostatic discharge (ESD) protection using the human body
model.
VCC
VREF P
The RESNTR pins are used to supply DC voltage to the VCO, as well as to
tune the center frequency of the VCO. Equal value inductors should be con-
nected to this pin and pin 13.
12
RESNTR-
RESNTR+ RESNTR-
LOOP FLT
4 kΩ
See pin 12.
13
14
RESNTR+
LOOP FLT
Output of the charge pump. An RC network from this pin to ground is used
to establish the PLL bandwidth. Diodes shown in the interface schematic
provide 3kV electrostatic discharge (ESD) protection using the human body
model.
VCC
LOOP FLT
This pin is used to set the threshold of the lock-detect circuit. A shunt
capacitor should be used to set an RC time constant with the on-chip
series 1k resistor. This signal is used to clamp (enable or disable) the MOD
IN circuitry. The time constant should be approximately 10 times the refer-
ence period. Diodes shown in the interface schematic provide 3kV electro-
static discharge (ESD) protection using the human body model.
15
16
LD FLT
VCC
1 k
Ω
LD FLT
Logic “High” input selects divide-by-64 prescaler. Logic “Low” input selects
divide-by-32 prescaler. Diodes shown in the interface schematic provide
3kV electrostatic discharge (ESD) protection using the human body model.
DIV CTRL
VCC
DIV CTRL
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
4 of 22
Rev A17 DS060712
RFMD [ RF MICRO DEVICES ]
